The overtravel spring assembly herein disclosed is used in automatic vehicle brake slack adjusters for measuring the amount of overtravel of the piston during a brake application operation and for preventing lock-up of the adjusting mechanism when such overtravel occurs.
The present structure of one form of overtravel spring assembly presently used comprises a cylindrical housing having an annular collar-like retainer welded in place at one end of the housing against which the corresponding end of a spring rests. The opposite end of the cylindrical housing is internally threaded for receiving a totally machined annular collar-like retainer after the spring has been prestressed to a desired degree. This known structure, due to machining and assembly operations is costly to produce.